The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
A nacelle, belonging to the thruster of the aircraft, generally has a structure comprising an air intake upstream from the turbine engine, a middle section intended to surround a fan of the turbine engine, a downstream section harboring thrust reversal means and intended to surround the combustion chamber of the turbine engine, and is generally completed by an ejection nozzle, the outlet of which is located downstream from the turbine engine.
The air intake comprises an intake lip adapted so that the air required for feeding the fan and internal compressors of the turbine engine may be optimally collected to the turbine engine on the one hand, and a downstream structure on which the lip is added and intended to properly channel the air towards the vanes of the fan on the other hand.
This downstream structure notably comprises an internal ring-shaped wall 1, illustrated in FIGS. 1 and 2, and an external cowl (not shown) radially spaced apart from the internal wall 1.
The internal wall 1 of the air intake structure is extended with a fan case belonging to the middle section of the nacelle in a direction parallel to the longitudinal axis of the turbine engine.
More particularly, the downstream end of the internal wall 1 of the air intake and the upstream end of the case of the fan each bear peripheral connection flanges 2,3 for assembling together said air intake and fan case, by means of attachment elements such as screws 4 or bolts.
In present air intake structures, as illustrated in FIGS. 1 and 2, the connection flange 2 of the air intake structure is respectively attached downstream from the acoustic panel of the internal wall 1 or on the acoustic panel itself by bolted elements 5.
The presence of the bolted elements 5 then requires local reinforcements in the flange plane which have an incidence on the mass of the air intake structure.
Further, such arrangements limit the dimensions of the acoustic panel of the internal wall 1 of the air intake structure, if it is desired not to deteriorate it by the arrangement of the bolted elements 5, as illustrated in FIG. 1.
Air intake structures are also known, in which the internal wall and the corresponding flange for connection to the fan case are integrated into a single part in composite material.
Now, in such a part, interlaminar shearing is seen at the adhesively bonded link between the flange and the acoustic panel of the internal wall.
There then exists a risk of delamination in the composite part which causes a significant lowering of the mechanical strength of the internal wall of the air intake structure, and even breaking of the latter.